Brake drum dolly

ABSTRACT

A dolly is provided for facilitating removal and installation of brake drums on vehicles. The dolly includes a frame having a cradle portion for supporting a brake drum. Wheels are rotatably mounted on the frame for moving the frame over a support surface into position beneath a brake drum. A handle projects from the frame for manually manipulating the frame into and out of position relative to the brake drum. An elevating linkage is provided for raising and lowering the frame relative to the wheels to lift and lower the brake drum relative to the vehicle.

This is a continuation of Application Ser. No. 08/884,351, filed Jun.27, 1997, now U.S. Pat. No. 5,975,543; which is a continuation ofApplication Ser. No. 08/582,233, filed Jan. 3, 1996, now U.S. Pat. No.5,735,538.

FIELD OF THE INVENTION

This invention relates to a dolly particularly adapted for facilitatingremoval and installation of brake drums on vehicles.

Background of the Invention

It is very difficult to handle outboard brake drums on trucks andtrailers in order to service or replace the drums or to perform serviceon the brakes and associated parts. Heretofore, the most commonprocedure in removing and installing brake drums has been by manualmanipulation. This is extremely difficult and dirty work and is prone tocause injuries, including serious back injuries. These operations havecaused a considerable amount of lost-time as well as workman'scompensation claims for a shop proprietor.

Outboard brake drums, such as used on large trucks, can weight as muchas 120 pounds each. They are very awkward to grasp and handle; they arepositioned at a height that requires a person to stoop or bend; and theyfrequently are positioned beneath an overhead obstruction, such as atruck or trailer bed.

Overhead lifts, hoists or cranes might be considered a logical solutionto these problems. However, it must be understood that vertical accessto the brake drums often is difficult or impossible because of theoverhead obstructions. In addition, such implements are prone to scratchor damage portions of the vehicle itself.

The present invention is directed to solving these problems by providinga very efficient, simple to operate and cost effective dolly which canbe used by an operator. In fact, the dolly is readily operable by anoperator's two hands and actually can be manipulated over a supportingsurface with a single hand.

SUMMARY OF THE INVENTION

An object, therefore, of the invention is to provide a simple, efficientand cost-effective dolly for facilitating removal and installation ofbrake drums on vehicles.

In the exemplary embodiment of the invention, the dolly includes a framehaving a cradle portion for supporting a brake drum. Wheels arerotatably mounted on the frame for moving the frame over a supportsurface, such as a floor, including into a position beneath the brakedrum. A handle projects from the frame for manually manipulating theframe including into and out of said position. Elevating means areprovided for raising and lowering the frame relative to the wheels tolift and lower the brake drum relative to the vehicle.

As disclosed herein, the cradle portion is concave generally in acurvature complementary to that of the brake drum. The frame includesstop means for abutting against an outside surface of the brake drum tofacilitate defining the position of the frame beneath the brake drum.Latch means are movably mounted on the frame for latching engagementwith the brake drum to hold the drum in the cradle portion of the frame.

A feature of the invention is to mount the wheel means on axle meansbelow the frame, with the handle being elongated and connected to theframe on an axis spaced above the axle means. Therefore, the frame canbe tilted about the axle means by raising and lowering the handle. Infact, the cradle portion of the frame is located forwardly of the wheelaxle means to amplify this tilting movement.

As disclosed herein, the elevating means is a toggle linkage connectedbetween the wheels and the frame. The linkage includes a first link armpivotally connected at one end thereof to the axle means and an oppositeend thereof to the frame. A second link arm is pivotally connected atone end thereof to the first link arm intermediate the ends thereof. Athird link arm is pivotally connected to the second link arm spaced fromthe one end thereof. The third link arm is pivotally connected to theframe at a location spaced from its point of connection to the secondlink arm. The third link arm is extendable to effect relative pivotingof the second and first link arms and, thereby, movement of the axlemeans relative to the frame. In the preferred embodiment, the third linkarm is provided as a turnbuckle type member to effect extending orretracting the third link arm. A manually rotatable crank is operativelyassociated with the turnbuckle member.

Other objects, features and advantages of the invention will be apparentfrom the following detailed description taken in connection with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of this invention which are believed to be novel are setforth with particularity in the appended claims. The invention, togetherwith its objects and the advantages thereof, may be best understood byreference to the following description taken in conjunction with theaccompanying drawings, in which like reference numerals identify likeelements in the figures and in which:

FIG. 1 is an overhead perspective view of the dolly of the invention, asthe wheels and handle would be resting on a support surface such as afloor;

FIG. 2 shows an operator having moved the dolly in position beneath abrake drum of a vehicle, with the operator manually manipulating theelevating means;

FIG. 3 is a side elevational view of the frame of the dolly in positionbeneath the brake drum;

FIG. 4 is a fragmented side elevational view of the latch means invarious positions;

FIG. 5 shows the operator using the dolly to transport the brake drumover the support surface; and

FIG. 6 shows the operator tilting the handle of the dolly upward todeposit the brake drum onto the support surface or floor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings in greater detail, the invention is embodiedin a dolly, generally designated 10, for facilitating removal andinstallation of a brake drum 12 on a vehicle. Although the dolly has awide range of applications, the dolly is particularly applicable forremoving and installing brake drums on trucks and trailers wherein thedrums may weigh as much as 120 pounds each. FIG. 1 shows the dollysimply resting on a support surface such as a floor. FIG. 2 shows anoperator having moved the dolly in position beneath the brake drum whichis still mounted on the vehicle outboard of springs 14 of the vehicle.FIG. 3 shows the dolly having moved the brake drum away from the vehiclein the direction of arrow "A" and off of brake pads 16.

More particularly, dolly 10 includes a frame, generally designated 18and including a forward cradle portion defined by a concave upper edge20 of a front wall 22 of the frame. The frame may be fabricated of metalmaterial, and front wall 22 is integrally joined to side walls 24 which,in turn, are connected by appropriate fastening means 26 to a rear crossbrace 28. A pair of wheels 30 are rotatably mounted on an axle 32running transversely beneath and spaced below the frame. The wheels areeffective for moving the frame over a floor and into and out of aposition beneath the brake drum as described above in relation to FIGS.2 and 3.

An elongated handle, generally designated 34, projects rearwardly offrame 18 for manually manipulating the frame over the floor and into andout of position relative to the brake drum. The handle is a telescopingshaft-like member and includes an outer handle portion 34a telescopedwithin an inner handle portion 34b. The length of the handle isadjustable by providing a plurality of axially spaced holes (not visiblein the drawings) for receiving a pin 36 extending through the telescopedhandle portions. A plastic grip 38 may be provided on the outer distalend of the handle. The extreme opposite end of the handle is fixed, asat 40, to front wall 22 of frame 18, as by welding. The handle also isfixed to brace 28 of the frame, as at 42.

Stop means are provided in the form of a pair of upwardly projectingarms 44 fixed by appropriate fastening means 46. The stop arms abutagainst an outside surface of brake drum 12, as best seen in FIGS. 2 and3, and effectively define the position of frame 18 beneath the brakedrum.

A latch arm 48 is pivotally mounted on a pin 50 extending between a pairof bracket plates 52 fixed between inner handle portion 34b and framebrace 28, as by welding. The latch arm has a hook portion 54 on thedistal end thereof. As seen best in FIG. 3, the latch arm is pivoted toa position wherein the hook portion latches inside the brake drum tohold the brake drum on frame 18 within cradle 20 thereof. FIG. 4 showsthat latch arm 48 can be located at different positions to accommodatedifferent sizes of brake drums simply by positioning pin 50 (FIG. 1)through one of a plurality of holes 56 in bracket plates 52.

Another feature of the invention is the provision of elevating means,generally designated 60, for raising and lowering frame 18 relative towheels 30 (i.e. the floor) to lift and lower the brake drum relative tothe vehicle. More particularly, elevating means 60 is provided in theform of a toggle linkage between the wheels and the frame. The linkageincludes a first link arm 62 pivotally connected at one end thereof toaxle 32 and an opposite end 64 thereof to one of the side walls 24 offrame 18. At this point, it should be understood that, while only oneelevating linkage 60 is provided at the right-hand side of frame 18, alink arm 66 similar to first link arm 62 is provided at the oppositeside of the frame between axle 32 and the side wall 24 of the frame, asis clearly seen in FIG. 1. Therefore, link arms 62 and 66 effectivelyallow frame 18 to move up and down relative to wheels 30 and thesupporting floor.

Elevating linkage 60 also includes a second link arm 68 pivotallyconnected at one end to first link arm 62 intermediate the ends of thefirst link arm. A third link arm 70 is pivotally connected to secondlink arm 68 at a pivot point 72 spaced from the pivot connection betweenthe first and second link arms. The third link arm is pivotallyconnected, as at 74, to side wall 24 of the frame at a location spacedfrom pivot point 72 between the third link arm and the second link arm.Generally, third link arm 70 is extendable to effect relative pivotingof second and first link arms 68 and 62, respectively, to effectivelyraise and lower frame 18 relative to axle 32 and wheels 30.

More particularly, third link arm 70 is provided in the form of atumbuckle type member having an outer portion 70a pivoted to side wall24, at 74. A threaded post 76 extends through outer portion 70a of thethird link arm and is threaded into a nut 77 integral with arm 70. Amanually rotatable crank 78 having a handle portion 80 is fixed tothreaded post 76 outside the outer portion 70a. Therefore, as the crankis rotated, threaded post 76 is rotated to move third link arm 70axially and thereby effect rotation of second and first link arms 68 and62, respectively.

The operation and manner of using dolly 10 now will be described.Referring first to FIG. 2, it can be seen that the operator has wheeleddolly 10 to a location for positioning frame 18 beneath brake drum 12.It can be seen clearly in this depiction that handle 34 is connected tothe frame spaced above axle 32. In addition, as seen in FIG. 3, theentire frame is located forwardly of the axle. Therefore, the operatorcan effect some degree of raising and lowering of the frame simply byraising and lowering the handle. In other words, referring to FIG. 2, bypressing down on handle 34 in the direction of arrow "B", the frame willrotate about axle 32 in the direction of arrow "C" and cause the frontof the frame (i.e. cradle edge 20 in FIG. 1) to elevate in the directionof arrow "D". If the frame still is not in a proper elevated positionfor movement beneath the brake drum, the operator rotates crank 78 inone direction or the other as indicated by double-headed arrow "E" tooperate elevating linkage 60 (FIG. 1).

Once the operator has properly positioned frame 18 beneath brake drum12, such as having stop arms 44 abut against the outside surface of thebrake drum, the operator will effect a final degree of lifting to freethe brake drum for movement of the drum axially off of brake pads 16 inthe direction of arrow "A" (FIG. 3). It can be seen in FIG. 2 that theoperator can effect two different types of lifting (or lowering) actionsby either of his or her hands. It can be seen that the operator's righthand is manually manipulating crank 78 while the left hand is grippinghandle 34. In actual practice, an operator may use elevating linkage 60and crank arm 78 to vertically located frame 18 for easy positioningbeneath the brake drum, and then use handle 34 to effect the actualfinal lifting of the brake drum itself, because of the considerablestrength of the handle and its simple lever-type mechanical advantage.

Once the brake drum is moved off of its brake pads in the direction ofarrow "A" as indicated in FIG. 3, the operator then can transport thebrake drum to another work station as indicated in FIG. 5. Once at thework station, the operator simply rotates handle 34 upwardly in thedirection of arrow "F" (FIG. 6) to deposit the brake drum onto thefloor. It can be seen in FIG. 6 that latch arm 48 will prevent the brakedrum from dropping onto the floor before being gently lowered thereon.At the work station, appropriate hoists can be used for effectingwhatever repairs are to be performed on the brake drum.

Whereas FIG. 1 shows dolly 10 with handle 34 resting on the floor, FIG.6 shows that the dolly can also be positioned in an upright positionwith frame 18 resting on the floor. This upright position isadvantageous to store the dolly in an out-of-the-way location, taking upminimal floor storage space.

It will be understood that the invention may be embodied in otherspecific forms without departing from the spirit or centralcharacteristics thereof. The present examples and embodiments,therefore, are to be considered in all respects as illustrative and notrestrictive, and the invention is not to be limited to the details givenherein.

What is claimed is:
 1. A dolly for facilitating removal and installationof brake drums on vehicles, comprising:a frame including a cradleportion for supporting a brake drum; a wheel assembly including an axlerotatably mounted relative to the frame for moving the frame over asupport surface including into position beneath a brake drum with theaxle generally centered beneath the brake drum and with the brake drumbeing supported on the cradle portion while the brake drum is stillmounted on a vehicle; a handle projecting from the frame to permitmanual manipulation of the frame into and out of said position; anelevator operable to raise and lower the frame relative to the wheelassembly in order to lift and lower the brake drum relative to thevehicle, said elevator comprising an elongated link pivotally mounted onsaid wheel assembly and operably coupled with a threaded, axiallyrotatable post, and a crank associated with said threaded post to effectselective rotation of the post and consequent pivoting of said link tolift and lower said frame; and a latch arm pivotally mounted on theframe and having a portion thereof oriented for latching engagement withthe brake drum to hold the brake drum in the cradle portion of theframe.
 2. The dolly of claim 1 further comprising an intermediatelinkage between said link and said threaded post.
 3. The dolly of claim1 further comprising an intermediate linkage between an end of said linkremote from said wheel assembly and said threaded post.
 4. A dolly forfacilitating removal and installation of brake drums on vehicles,comprising:a frame including a cradle portion for supporting a brakedrum; a wheel assembly including an axle rotatably mounted relative tothe frame for moving the frame over a support surface including intoposition beneath a brake drum with the axle generally centered beneaththe brake drum and with the brake drum being supported on the cradleportion while the brake drum is still mounted on a vehicle; a handleprojecting from the frame to permit manual manipulation of the frameinto and out of said position; a rotatable crank; an elongated, threadedrod coupled to the crank for axial rotation of the rod; a linkageassembly including an elongated link pivotally coupled with said wheelassembly and operatively attached to said threaded rod to effect raisingand lowering of said frame upon rotation of said crank in respectivedirections; and a latch arm pivotally mounted on the frame and having aportion thereof oriented for latching engagement with the brake drum tohold the brake drum in the cradle position of the frame.